Integrated circuits, the key components in thousands of electronic and computer products, are generally built layer by layer on a silicon substrate. One common technique for forming layers is called chemical-vapor deposition (CVD.) Conventional CVD systems not only form layers that have non-uniform thickness, but also have large chambers that make the CVD process wasteful and slow. Accordingly, the inventor devised new CVD systems, methods, and apparatuses. One exemplary CVD system includes an outer chamber, a substrate holder, and a unique gas-distribution fixture. The fixture includes a gas-distribution surface having holes for dispensing a gas and a gas-confinement member that engages or cooperates with the substrate holder to form an inner chamber within the outer chamber. The inner chamber has a smaller volume than the outer chamber, which not only facilitates depositions of more uniform thickness, but also saves gas and speeds up the deposition process.